Real numbers x and y, f(x+y)=f(x)+f(y)+1. If f(1)=2, what is f(3)?

  • Thread starter Xasuke
  • Start date
  • #1
13
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Ok, I'm sure this is an easy problem and all, but it's pissing me off. I'm probably just not understanding it.

The function f has the property that for any real numbers x and y, f(x+y)=f(x)+f(y)+1. If f(1)=2, what is f(3)?

help.
 

Answers and Replies

  • #2
Tide
Science Advisor
Homework Helper
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Just use the information provided to find f(2) from which f(3) = 8 follows.
 
  • #3
13
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wow... I feel completely lost.
How do I find f(2)?
 
  • #4
dav2008
Gold Member
609
1
f(2)=f(1+1)

If you are given that f(x+y)=f(x)+f(y)+1

then it would be logical to conclude that

f(1+1)=f(1)+f(1)+1 and I think you can take it from there
 
  • #5
13
0
Oh my.. Thanks. I'm such an idiot =)
 

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